| AVS 60th International Symposium and Exhibition | |
| Thin Film | Friday Sessions |
| Session TF+EM+NS+SS-FrM |
| Session: | Thin Film: Growth and Characterization III |
| Presenter: | P. Morgen, University of Southern Denmark |
| Authors: | P. Morgen, University of Southern Denmark R. Dhiman, University of Southern Denmark J. Hvam, University of Southern Denmark A. Gomes Silva, Universidade Nova de Lisboa, Portugal K. Pedersen, Aalborg University, Denmark Z. Li, Aarhus University, Denmark |
| Correspondent: | Click to Email |
Electronic devices fabricated from SiC- or SiC/Si epitaxial wafers will need surface passivation and insulating coatings. In earlier work [1], we described a procedure for forming thin (1 nm) Al-oxide layers on Si surfaces, at processing temperatures of around 6000C or slightly higher, resulting in an atomically sharp interface and no silicate formation.
We have adopted the same procedures to a system of SiC/Si, formed by a remote CH4 plasma interacting with heated Si surfaces in UHV [2]. After growing the SiC/Si system (SiC thickness between 0.5 and 25 nm; polycrystalline) a self-limiting Si-oxide layer was grown on the surface, with a thickness of around 1 nm, at 7000C. On top of this layer we deposited approximately 1 nm of Al with a Knudsen atomic source (all steps in UHV) and then reacted it thermally (at 6000C) with the Si-oxide. We monitored all the process steps and the resulting structures of the layers and the interface using synchrotron radiation induced core level photoemission at ASTRID, Aarhus, Denmark. We found similar qualities with this procedure, as for Si, i.e. an atomically sharp interface between Al-oxide and SiC, which is better than for conventional ALD. This reaction scheme offers self-limiting behavior both of the oxidation to create Si-oxide, and of the conversion into Al-oxide, which only needs a sufficient amount of Al to affect the total conversion of the Si-oxide, while excess Al will leave the system at sufficiently elevated temperatures.
[1] Nanostructured Materials in Different Dimensions for Sensing Applications, Per Morgen, Joanna Maria Drews, Rajnish Dhiman, and Peter Nielsen, in: NATO Science for Peace and Security Series B: Physics and Biophysics , Vol. 2011, Nr. 8, 2011, 257-273.
[2] Growth of thin SiC films on Si single crystal wafers with a microwave excited plasma of methane gas, Rajnish Dhiman, and Per Morgen, Thin Solid Films, in press 2013, [http://dx.doi.org/10.1016/j.tsf.2013.03.090]